/Engine/Source/Runtime/OpenGLDrv/Public/OpenGLDrv.h
Set a resource on texture target of a specific real OpenGL stage. Goes through cache to eliminate redundant calls.
void CachedSetupTextureStage ( [FOpenGLContextState](API\Runtime\OpenGLDrv\FOpenGLContextState) & ContextState, GLint TextureIndex, GLenum Target, GLuint Resource, GLint BaseMip, GLint NumMips )